We had the same issue on some computers and decided not to upgrade for now. Do you happen to be running virtual desktops? I believe TCD 1.6 got rid of OpenGL and uses Directx only, which caused our issue. Maybe your issue is similar?

If you have had Tekla BIMSight or Trimble Connect Desktop installed on your machine by two or more different accounts, that causes problems of having multiple versions of plugins in the machine.

First you should check with all needed user accounts that Tekla BIMsight, Trimble Connect Desktop and all plugins are removed. Plugins start with either "Trimble Solutions ImportSDK" or "Tekla Model Sharing Foundation".

Then you can install Trimble Connect Desktop (and Tekla BIMsight if needed). Note: You need to install Tekla BIMsight first. They both use the same plugins and you want to install last the newer ones that come with Trimble Connect Desktop.